"Mega Nests: where did they come from and what can be done about them?"

#PokemonGO: Mega nests (or meganests) are one of the most interesting phenomena found in Pokémon GO. These nests impact thousands, if not tens of thousands of trainers every day. Recent discussions have shown that they are often still not very well understood with many trainers being unsure of their origins or even being unaware that they exist.In order to explore the intricacies of what the community has come to term “mega nests”, it is important to first understand the basics behind Pokémon GO’s nest feature.Some of the key facts to know about nests are:Niantic does not use the term “nest” in official contexts. Instead they will make statements along the lines of “different Pokémon may appear in parks around you” when referring to aspects of the feature .Nests are locations in Pokémon GO where a particular species is more likely to appear. It is generally accepted that around 25% of all spawns at a nest will be the nesting species.Nests are associated with certain mapped areas from Open Street Map (OSM). Each nesting area will have a single nesting species. Spawn points that occur within these areas display nesting properties.In order for an OSM area to be a nest in Pokémon GO, it must have a nesting tag associated with it. Tags are used in OSM in order to designate and identify what map features are. For example, tags are used help mark features such as houses, parks, trees, forests, rivers and roads.It is possible to have a nest within a nest, or nested nests if you will. This commonly occurs in situations such as a playground being mapped within a park or a pitch being marked within a recreation ground.A nesting area being present on OSM does not guarantee that it will contain spawn points. This means Pokémon do not always spawn in all potential nesting areas.Niantic does not use live OSM data in Pokémon GO. Currently, nesting areas are based on OSM map data from the 9th of April, 2018.While some nests appear on the game map as dark green, the visual data used by Pokémon Go is from a different date. Additionally, only a select handful of nesting tags show as dark green (parks, golf courses and recreation grounds).Nests migrate once every two weeks, and also after certain updates.Unlike EX raid gyms, nests support OSM relations. This means more areas can be nests.Nesting tags:Over the past years, the Pokémon GO community has identified a number of tags that can cause nests. Some of these tags are only used a handful of times around the globe. It is possible that this list is not complete, with some niche nesting tags left undiscovered:"leisure"="golfcourse", "leisure"="park", "landuse"="farmland", "landuse"="farmyard", "leisure"="garden", "landuse"="grass", "landuse"="meadow", "landuse"="orchard", "landuse"="recreation_ground", "leisure"="recreation_ground", "landuse"="vineyard", "leisure"="pitch", "leisure"="playground", "natural"="grassland", "natural"="heath", "natural"="scrub", "natural"="plateau", "natural"="moor" and "landuse"="greenfield"These tags are broadly associated with natural, agricultural and leisure land uses. Though, there are some notably absent tags in this list. One missing tag is “natural”=”wetland”, which is known to completely block spawns. Another absent tag is “leisure”=”nature_reserve”, which has suggested to have nesting properties in some Niantic communications, but does not actually nest on its own.What is a mega nest?:The term mega nest is commonly used by the Pokémon Go community to describe very large nests. For the sake of this post, we will define a mega nest as the following:A very large nest that encompasses a large number of distinct and unrelated land uses over a significant geographic area.Why are mega nests a problem?:There are two primary complaints regarding mega nests:The current nesting pool is made up of a significant number of generally uninspiring Pokémon species. As nests override approximately a quarter of all spawns, areas covered by mega nests are flooded by these Pokémon for weeks at a time.Mega nests appear to override event spawns in certain contexts, such as the otherwise increased Psyduck spawns from the global component of the Porto Alegre Safari Zone event. Trainers living deep within mega nests have to travel significant distances to make the most out of events.Affected locations:There are two major cities that overlap well known mega nests, however, both have different causes and potentially different solutions. We are able to apply our understanding of nests to explore how these mega nests function and why they exist.Long Island landmass, New York:The entirety of the Long Island landmass is a mega nest. In this case, the nest is the result of a mapper assigning the “natural”=”scrub” tag to the island while attempting to map bird habitats. While it was an unintentional edit that was quickly corrected, Niantic’s nest data was sourced before it was fixed. The Long Island mega nest came into being with the April 2018 map update. This update saw nests, spawns and blocked areas changed to reflect OSM data from earlier that same month.Suggested solutions:Of the cities most impacted by mega nests, New York is likely the easier of the two to fix. There are a number of ways this could be done:Update nesting data to a more current version of the OSM map. The offending natural=scrub tag was only present for a matter of hours. Updating to practically any other map version would remove this nest.Manually remove the natural=scrub tag from the Long Island landmass’s relation in the existing map version that Niantic is using.Technical information:Affected area: Relation 3955977 (Long Island)Scrub Changeset: #57926221Scrub Removed Changeset: #57928718Glien, Nauener, Teltow, Barnim and Lebus Plateaus, Berlin:Berlin was one of (if not the) first cities to be influenced by mega nests. In this case, they are linked to a series of large “natural”=”plateau” areas mapped in and around Berlin.Unlike the case of Long Island, the Berlin mega nests are technically the result of valid OSM edits and should not be removed*. Updating to a new version of OSM data will not fix the Berlin mega nests as they are still present on the OSM map.*At this time, one plateau has been modified. This is possibly an undiscussed change and there’s a chance it will be reverted.Suggested solutions:Remove “natural”=”plateau” from the list of nesting tags. This tag is only used a small handful of times globally. Outside of Berlin, the tag typically occurs in very remote locations. Several of the current uses of the tag appear to have been applied incorrectly, which lowers the number of valid uses of the tag even further.Manually disable the nests linked to the 5 plateaus around Berlin.Technical information:Affected areas: Relation 2218269 (Barnim), Relation 2218272 (Lebus), Relation 2218275 (Teltow), Relation 2218273 (Nauener Platte), and Relation 2218271 (Glien)Discussion:In their own right, mega nests have led to a number of important insights into otherwise hidden game mechanics for the Pokémon Go community. But, for everything we can learn by observing these locations, they impact far too many trainers to be something that is left ignored.Some have said that other trainers such as those who live in rural locations may have things worse. This is probably true, however, fixing one issue does not have to come at the cost of fixing others.The causes and problems associated with mega nests have been clearly identified by the community for some time. Hopefully, Nianic has also come to similar findings either through their own efforts or following along with community discussions, and we will see solutions to these issues in the near future.Mandatory link to Tips for new (Pokemon Go) mappers: http://bit.ly/2EnYEZC) via /r/TheSilphRoad http://bit.ly/2S2zUQb